A variety of tools have been described for assisting in the finishing work for internal corners of dry wall panels in building interiors. The appearance of the interior to some extent relies upon the success or otherwise of the joint formation and finish. This is because the finishing work sequence may involve the mixing of plaster, the application of plaster, the smoothing of plaster, the drying of plaster, the sanding of the dried plaster and the brushing of the dried plaster.
In the Applicant's Innovation Patent No. 2013100174 (published Mar. 21, 2013), a hand pump is described for extruding a bead of comparatively viscous, water-based plaster. This pump has a nozzle that deposits a continuous bead of plaster into the corner. The volume of plaster deposited in this way is calculated to be sufficient to cover the dry paper tape applied beforehand to the edges of the drywall panels but not much of the panel's surface. A smoothing trowel called a corner glazer may be mounted on a handle, which allows the trowel to articulate when used to smooth the plaster. This arrangement relies on integral springs to resist deformation of wings of the glazer. However, if viscous plaster is used, the tool tilts off center and wing concavity forms convex strips in the carrier, which is inconvenient, and incurs additional cost, labor, time, and extra compound, requiring further sanding.